Final answer:
The key difference in political structures between Europeans and Ottomans in 1450-1750 was that Ottomans relied on absolute monarchies while Europeans experienced various governance systems including feudalism and rising absolute monarchies.
Step-by-step explanation:
The correct answer that distinguishes the political structures of Europeans from the Ottomans during the period 1450-1750 is b) Ottomans relied on absolute monarchies. European political entities during this time experienced a variety of governance systems, ranging from feudalism with many semi-autonomous entities to the rise of centralized, absolute monarchies as seen during the age of absolutism. Conversely, the Ottoman Empire was marked by a strong, centralized system of governance under the rule of a sultan who held absolute power. The Ottoman sultans maintained a highly organized administrative structure to rule over their vast empire, which included various regions and peoples. Though European monarchs also sought to consolidate power, they often dealt with more decentralized structures, especially earlier in this period, and numerous challenges to their authority.